Understanding the nature of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="normal">Ω</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>2012</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:math> in a coupled-channel approach
Qi-Fang Lü, Hideko Nagahiro, Atsushi Hosaka
Abstract
We perform a systematic analysis of the mass and strong decays of the $\mathrm{\ensuremath{\Omega}}(2012)$ resonance in a coupled-channel approach of a bare three-quark state and a composite meson-baryon state. Besides the coupling of the bare state and ${\mathrm{\ensuremath{\Xi}}}^{*}\overline{K}$ channel, the effective meson-baryon interactions are also included. We find a pole with a mass of 2008 MeV by solving the Bethe-Salpeter equation. The calculated decay widths and its ratios of branching fractions ${\mathcal{R}}_{\mathrm{\ensuremath{\Xi}}\overline{K}}^{\mathrm{\ensuremath{\Xi}}\ensuremath{\pi}\overline{K}}$ agree well with the new experimental measurement by the Belle Collaboration. Our results suggest that both three-quark core and ${\mathrm{\ensuremath{\Xi}}}^{*}\overline{K}$ channel are essential for the description of the $\mathrm{\ensuremath{\Omega}}(2012)$ resonance. We expect that present calculations can help us to better understand the nature of $\mathrm{\ensuremath{\Omega}}(2012)$ resonance.